This invention relates generally to earth working implements. More particularly, the invention relates to a novel lock and lift mechanism for folding wing implements, such as disc harrows and the like. The novel lock and lift mechanism allows the wing constituents of the implement to be securely locked in an operative position without maintaining pressure in the mechanism as the implement traverses the ground.
In the farm industry the trend toward more powerful tractors and the desirability to work larger areas of ground have resulted in the increasing of the weight and working width of implements, such as disc harrows and the like. Generally the working width of the implement has been increased by hinging, to a main implement section, a pair of extension implement wings which can be swung about the axis of a hinge to a folded position for transporting or storage of the implement and into a lowered or working position when desired. The use of such foldable wings has facilitated passage of the implements through gates and over roads as well as storage of the implement. However, one problem which has occurred in the use of such folding implements is that a means must be provided for maintaining the wings rigid with respect to the main implement section when the implement is in use so that the disc or other ground working tools of the wings penetrate the ground at the same depth as those of the central or main section. Thus, one of the principal considerations in the design of a folding frame implement is to provide a locking means for locking the extension wings in the rigid, working position. It is, of course, desirable that the locking means be both simple to operate and dependable in performance.
Heretofore, numerous lock and lift mechanisms have been proposed by the prior art which would allow a wing to be lifted, lowered and rigidly secured or locked to the main section when in the lowered position and yet would allow the operator to lift the wing relative to the implement when transporting or storing the implement. Some of such mechanisms are shown in U.S. Pat. Nos. 3,814,191; 3,692,121; 3,650,333; 3,693,724 and 2,719,682.
A need has long been recognized in the farm industry for a reliable and simple lock and lift mechanism for a foldable implement which is durable and allows the wings to be secured in place.
Accordingly, the present invention provides an improved lock and lift mechanism for a foldable implement having a main section and a least one wing pivotally mounted to the main section for folding relative thereto. The mechanism allows the wing unit to be locked in a working position, unlocked, and raised for transporting of the unit by operation of a single power source. Further, according to the invention, an improved lock mechanism is provided which does not require pressure to be maintained on the wing sections when the sections are in an extended working position and yet while simple to construct is durable and reliable in service.